The distance is the object from the mirror will be 5cm.
A mirror equation is an equation that relates object distance and image distance to focal length. It is often referred to as a mirror formula.
The object distance in a spherical mirror is the distance between the object and the pole of the mirror (u).
The given data in the problem is;
Image height = 18cm
Object height = 10cm
u is the object distance
v is the image distance = 9 cm
From the symmetry of the triangle;
[tex]\frac{image \ height }{object \ height} = \frac{v}{u} \\\\ \frac{18 }{10} = \frac{9}{u}\\\\ \rm u=\frac{90}{8} \\\\ u = 5\ cm[/tex],
Hence the distance is the object from the mirror will be 5cm.
To learn more about the mirror equation refer to the link;
https://brainly.com/question/3229491
